Involuntary addiction of the newborn is an important health problem resulting from the epidemic increase of illicit drug usage in the past decade. Narcotic and sedative drugs may have harmful effects upon the CNS of the unborn infant. There is no reliable clinical method for evaluating neonatal CNS depression (or excitation) except in the glossly obtunded (or agitated) infant. Therefore is has been difficult to therapeutically modify the CNS complications associated with the passive narcotic addition. An objective technique for evaluating CNS activity as a function of sucking behavior has been developed in our laboratory. This method has been used to measure drug effects upon the infant as early as the first day of life, and may prove of value in assessing the influence of maternal narcotic addition upon the newborn as well as to evaluate the influence of drugs used in treating the narcotic withdrawal syndrome. A quantitative method for measuring the level of drug dosage during narcotic withdrawal.